Troy Tulowitzki is still searching for his missing production 11 months after leaving Coors Field.

Troy Tulowitzki returned to Coors Field last night for the first time as a visiting player, facing the Rockies nearly 11 months after the blockbuster trade that sent the five-time All-Star shortstop from Colorado to Toronto. Because the Blue Jays went 31-10 with Tulowitzki in their lineup last season and made the playoffs for the first time since 1993 the trade was immediately labeled a success, but Tulowitzki didn’t actually play all that well in those 41 games and his contract meant neither team involved was viewing the deal as strictly a short-term move. Tulowitzki’s mediocre performance has continued this season, which has to be worrisome for the Blue Jays given that he’s 31 years old and signed through 2020 at an average annual salary of around $20 million.

When the Blue Jays acquired Tulowitzki they did so knowing that his raw hitting numbers would decline because that’s just how things work with Rockies hitters. Coors Field undeniably boosts offense, often to extreme degrees, and hitters departing the Rockies can generally be counted on to post less gaudy raw numbers in their new homes. However, projecting how Rockies hitters will fare elsewhere can be tricky due to a potential “hangover” effect playing home games at altitude can have on a player’s performance in road games. In other words, it’s not always as simple as taking a longtime Rockies hitter’s road numbers and penciling those in as his overall numbers, because the road numbers might be underrepresenting his true, non-Coors Field talent level.

Tulowitzki spent the first decade of his career calling Coors Field home and took full advantage, hitting .321/.394/.558 in 526 games there compared to .276/.349/.468 in 522 road games. Even with a hangover effect possibly dragging them down those road numbers alone would have made Tulowitzki the best-hitting shortstop in baseball from 2006-2015, so the Blue Jays gladly would have signed up for .276/.349/.468. Instead he’s hit just .226/.306/.405 in 95 games following the trade, including .214/.294/.423 in 54 games this year. Once the king of good-hitting shortstops, his .717 OPS ranks 15th among the 26 players who’ve logged at least 50 games at the position this season and Tulowitzki is the third-oldest player in that group. His post-trade fall is magnified even further by the emergence of a potentially historic group of young shortstops.

There are no givens in baseball. A 10-run lead can evaporate under the misdirection of a tired bullpen, a no-hitter can be lost on a misplayed fly ball, and a ninth-inning tie can be broken on a walk-off balk. Still, there are certain markers which, once they are passed, provide a feeling of security.

Sometimes, a hitter adjusts so quickly that it’s hard to tell exactly what he’s doing, as he’s doing it. Perhaps it’s a new front-foot tap that’s helped him get his timing down on that tough fastball, and he debuts it on a Sunday and sees success with it right away. Perhaps it’s a sudden recognition of a particular pitch, out of a particular arm slot, that allows him to start crushing before anybody really notices how it’s happening. Perhaps. It doesn’t often happen that fast.

Half the American League might have regrets every time they check an A's box score these days.

Danny Valencia made his major-league debut in 2010, joining the Twins as a 25-year-old former 19th-round draft pick with a modest minor-league track record. He hit .311/.351/.448 in 85 games as a rookie to force his way into Minnesota’s plans, at which point he was handed the Opening Day job in 2011 and remained the starting third baseman all season. He quickly turned back into a pumpkin and by mid-2012 the Twins had tired of him on and off the field.

They traded Valencia to the Red Sox for a non-prospect and three months later the Red Sox sold him to the Orioles, who kept him for a year before sending him to the Royals for little in return. Six months later Valencia was traded from the Royals to the Blue Jays in a low-wattage swap and he was placed on waivers a year after that, when the A’s claimed him. Valencia changed teams five times in less than three years while spending much of that stretch in the minors.

He looked like the epitome of a replacement-level player. Not capable enough defensively to be trusted at third base, but not good enough offensively versus right-handers to warrant a full-time job at first base or designated hitter. Valencia was a 31-year-old platoon corner infielder with a reputation for too much … well, let’s call it swag. If anything, hanging around for as long as he did without being a former top prospect was a victory in itself. But then, just as it looked like Valencia might be running out of stops to make, he started crushing the ball.